JPS6095696A - Fire alarm - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Technical Field The present invention relates to a fire alarm that detects fire using an infrared image element and a logic circuit.

(b) Prior art and its problems Various types of fire alarms are known. This is the warm (temperature) method. However, since each of these detectors (notifiers) frequently malfunctions, their reliability has not been established. This was not due to a malfunction or incorrect operation of the detector itself, but rather because it lacked the ability to distinguish between a fire and other phenomena such as steam or cigarette smoke, even if it was operating normally. be. In order for machines to automatically detect fires, it is necessary to imitate the human perceptual system, but with conventional technology, there was no device that could imitate this so-called intellectual ability.

(C) Structure of the Invention The present invention is a device that mechanizes the most basic human perceptual activity, and uses the eyes to see the size of a fire and determine whether or not it is a fire. It has a function to inform you. To achieve this function, we first need eyes. It is not enough for the eye to simply detect the appearance, shape, color, etc. of objects; it must be able to discern fire. To do this, first, it is necessary to determine whether the fire is simply a cold object with the color of fire by identifying the temperature using infrared rays. The second method is to widen the identification range as shown in FIG. 2 to identify the size of the heat source. This includes:
A planar sensing element with multiple pixels is essential. By using this element, it is possible to
- The shape and size of objects can be replaced with electrical signals. 3rd K,
After this element detects and replaces it with an electrical signal, a logical operation circuit is required that has the same function as the brain to determine that there is a fire. A fire could only be detected by logical calculations when it was determined that the heat source was continuously distributed in a planar shape and had an area. Therefore, a signal indicating the occurrence of a fire is issued.

It is clear that the fire alarm of the present invention, which is characterized by having the above-mentioned functions, will make disaster prevention systems even more effective for hotels, guest rooms of inns, high-rise residential buildings, etc., where reliability is especially required.

Example FIG. 3 shows a schematic diagram of a fire alarm according to the present invention.

A planar infrared sensing element 5 is included in the detection optical system that uses an ultra-wide-angle lens 4 to obtain a wide field of view and a deep depth of focus.
combined. The planar sensing element was formed with 100×100 pixels. As a result, it has become possible to monitor and detect heat sources in a room with a floor area of about 5 m x 7 m in a section of 5 cs x 7 cm. As shown in Fig. 4, when a fire broke out and the size of the fire reached several tens of pots or more, it was determined that there was a fire. However, it was also possible to prevent it from being activated by a cigarette, a simple match, or the flame of a lighter. In addition, it was also possible to measure the continuous presence time of the flame at the same time as the area, so that a fire could be determined only when the flame continued for 30 seconds or more, for example. This means that, for example, a fire in a kitchen can be easily distinguished from flames caused by simple cooking, and can also be used as an effective fire alarm in Chinese restaurants where cooking is often accompanied by flames. became possible. Also, for fixed heat sources,
It was also possible to manipulate the thermal image area in advance using logical operations and identify only the occurrence of new heat sources.

As described above, since the fire alarm of the present invention is capable of intelligent processing, it has an extremely advanced discrimination ability similar to that of the human eye and brain, and in particular, it has an extremely advanced discrimination ability that is not possible with conventional fire alarms. It can be used stably even in harsh environments, and is extremely useful for disaster prevention and safety.

[Brief explanation of the drawing]

FIG. 1 shows a fire alarm according to the conventional method, and FIG. 2 shows an example obtained by the present invention. FIG. 3 shows the configuration of the present invention, and FIG. 4 shows image conditions during a fire and under normal conditions. FIG. 4(A) shows an image on the planar sensing element to be masked, and FIG. 4(B) shows a normal visual field. (C) shows the visual field in an abnormal situation (in the event of a fire), and (D) shows an image on the planar TO8 sensor in an abnormal situation. 1: Room 2: Fire alarm 3: Fire source 4: Wide-angle lens 5: Planar sensing element 6: Logic circuit 7: Alarm circuit 8: Mask pixel 9: Abnormality detection pixel

Claims (1)

[Claims] (+) In a method of detecting the occurrence of a fire using infrared rays emitted from a heat source, the size of the heat source is converted into an electrical signal by a planar sensing element having a plurality of pixels, and the area is calculated by a logic circuit, A fire alarm system that detects the occurrence of a heat source over a predetermined area as a fire and issues an alarm.